Setting Up

5-57

9161-A2-GH30-30 April 1998
Setting Up the Communication Port to Support an External Device
NOTE:
To detect when the external device connection has been lost, the
communication port’s DTR lead should be connected to the external device’s
DSR lead using a standard EIA-232 crossover cable (the communication
port’s DTR lead is monitored for loss of connection). The external device
must be configured to drop DSR when a disconnect occurs, and to ignore
DTR.
Use the External Device Options screen (see Table 5-11) to set up the COM port
to support an external device such as a modem or a PAD. These options control
call processing for an external device.
Configuration Edit/Display
→
User Interface
→

External Device

Table 5-11. External Device (COM Port) Options (1 of 3)
External Device Commands
Possible Settings: Disable, AT, Other
Default Setting: Disable
Specifies the external device commands to be sent out from the COM port to control the
device.
NOTE: The Carrier Detect (CD) lead detects loss of the external device, therefore
the external device must not force CD on.
Disable – Commands are not sent out from the communication port.
NOTE: You
must
use this setting if you have an async terminal connected to the
COM port.
AT – AT commands are sent out from the COM port. All AT command strings end with a
carriage return (hex 0x0D) and a line feed (hex 0x0A).
Other – Commands configured by the user are sent out from the COM port.
CAUTION: You must
not
use this setting if you have an async terminal connected to
the COM port.
NOTE: Connect Prefix, Connect Indication String, Escape Sequence, Escape
Sequence Delay, and Disconnect String options will only be used when the
setting is Other. Refer to the Control Characters table on page 5-60.
Dial-In Access
Possible Settings: Enable, Disable
Default Setting: Disable
Controls whether external devices can dial-in to the T1 access unit through the
communication port (based on the Communication Use configuration option setting).
Enable – Answers incoming calls and establishes connection to the remote terminal or
IP address.
Disable – Does not answer incoming calls. Refer to the Control Characters table on
page 5-60.